Quote:
Originally Posted by

**mtsalmela80** I'm having trouble with the handicap, as I mostly play 9 holes, in fact only played 18 holes once so far this year.

My scores this year are as follows:

101 - 70.1/121

45 - 34.5 / 122

43 - 34.5 / 122

49 - 34.5 / 122

Originally I just put in 18 in golfshot, but tried to use their automated handicap system, and ended up with like a 36.4 or something, does that seem accurate??

How does the math work? Where does the differential come from?

What would be the most accurate way to assess a handicap given mostly 9 hole scores?

This should help get you started. As noted the differential is: the score you shot minus the course rating. Take that number and multiply by 113. Take that result and divide by the course slope. Round to the nearest 10th. .5 round higher

101-70.1 = 30.9

30.9*113 = 3491.7

3491.7/121 = 28.85

Differential is 28.9

When you combine 9 hole scores you add the course ratings together but not the slope. The slopes get averaged.

For your first two 9 hole scores:

45+43 = 98

The rating would be 69.0/122

98-69.0 =29

29*113 =3277

3277/122 = 26.86

Differential is 26.9

Once you get 20 differentials take the 10 lowest. Compute the average of these 10. Take that number and multiply by .96 This result does not get rounded up. Just drop any numbers after the 10th. That's your handicap index.

To find out what your handicap is for a particular course take your handicap index and multiply it by the slope of the tees you're playing and then divide the result by 113. Round to the nearest whole number, .5 rounded higher.

Until your reach 20 differentials you can start computing a handicap index with just 5 differentials.

If you have 5-6 scores use the 1 lowest differential.

7-8 scores use the lowest 2 differentials

9-10 scores use the lowest 3 differentials

11-12 scores use the lowest 4 differentials

13-14..........................lowest 5

15-16..........................lowest 6

17...............................lowest 7

18................................lowest 8

19................................lowest 9

20...............................lowest 10

Once you have more than 20 scores, use the most recent 20 to get your lowest 10 differentials

If you want to know how what a "R" index is and how to compute it.......that's going to have to wait.